The overall goal of the project is to provide an accurate and comprehensive computer model of the entire auditory periphery that will simulate the cochlear-partition macromechanical and micromechanical vibrations, the hair-cell voltages, and the auditory-nerve-fiber discharge patterns produced by any acoustic signal presented anywhere in space. This model will be built around a currently working model of cochlear- partition vibrations (hydrodynamics) that was developed during the last grant period. The project has 3 specific aims. The first aim is to improve the accuracy of the current hydrodynamic model. Of particular importance is the low-frequency section of the model, which appears to require fundamentally different simulation than does the high-frequency section. The second aim is to expand the model by including representations of other parts in the peripheral transduction process: the middle and external ears, the hair-cell transduction processes, the hair- cell/afferent-nerve-fiber synapses, and the efferent systems. The third aim is to adapt the model, now representing the cat's periphery, to represent that of the human and the mustached bat.